On Fri, Nov 30, 2018 at 09:15:13AM +0800, Chao Fan wrote: >On Thu, Nov 29, 2018 at 12:32:46PM -0500, Masayoshi Mizuma wrote: >>Hi Chao, >> >>Thank you for your continued working. > >Thanks for your test. > >> >>Could you please build your patches before sending? > >Sorry for the mistake, I build it with the whole patches. >I found there are some problems with the method to splite patch. >I will rework on it and build every commit. > >Thanks, >Chao Fan > >>Your patches depend on the following kconfig, >>so please build them under the config combination. >> >>RANDOMIZE_BASE >>MEMORY_HOTREMOVE >>EARLY_PARSE_RSDP >>KEXEC >>EFI
Hi Masa, After retest, I make clean and make again. I met the problem is the useless #endif issue you mentioned. But I found both: #ifndef BOOT_STRING EXPORT_SYMBOL(kstrtoull); and EXPORT_SYMBOL(kstrtoull); #ifndef BOOT_STRING work for me. So I don't know the key problem, cause the config you mentioned are y. Thanks, Chao Fan >> >>Thanks, >>Masa >> >>On Thu, Nov 29, 2018 at 04:16:26PM +0800, Chao Fan wrote: >>> ***Background: >>> People reported that KASLR may randomly choose some positions >>> which are located in movable memory regions. This will break memory >>> hotplug feature and make the movable memory chosen by KASLR can't be >>> removed. >>> >>> ***Solutions: >>> Get the information of memory hot-remove, then KASLR will know the >>> right regions. Information about memory hot-remove is in ACPI >>> tables, which will be parsed after start_kernel(), so that KASLR >>> can't get the information. >>> >>> Somebody suggest to add a kernel parameter to specify the >>> immovable memory so that limit KASLR in these regions. Then I make >>> a patchset. After several versions, Ingo gave a suggestion: >>> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1634024.html >>> Follow Ingo's suggestion, imitate the ACPI code to parse the ACPI >>> tables, so that the kaslr can get necessary memory information in >>> ACPI tables. >>> I think ACPI code is an independent part, so imitate the codes >>> and functions to 'compressed/' directory, so that kaslr won't >>> influence the initialization of ACPI. >>> >>> PATCH 1/5 Add get_acpi_rsdp() to parse RSDP in cmdline from KEXEC >>> PATCH 2/5 Add efi_get_rsdp_addr() to find RSDP from EFI table when >>> booting from EFI. >>> PATCH 3/5 Add bios_get_rsdp_addr() to search RSDP in memory when EFI >>> table not found. >>> PATCH 4/5 Compute SRAT table from RSDP and walk SRAT table to store >>> the immovable memory regions. >>> PATCH 5/5 Calculate the intersection between memory regions from e820/efi >>> memory table and immovable memory regions. Limit KASLR to >>> choosing these regions for randomization. >>> >>> v1->v2: >>> - Simplify some code. >>> Follow Baoquan He's suggestion: >>> - Reuse the head file of acpi code. >>> >>> v2->v3: >>> - Test in more conditions, so remove the 'RFC' tag. >>> - Change some comments. >>> >>> v3->v4: >>> Follow Thomas Gleixner's suggetsion: >>> - Put the whole efi related function into #define CONFIG_EFI and return >>> false in the other stub. >>> >>> v4->v5: >>> Follow Dou Liyang's suggestion: >>> - Add more comments about some functions based on kernel code. >>> - Change some typo in comments. >>> - Clean useless variable. >>> - Add check for the boundary of array. >>> - Add check for 'movable_node' parameter >>> >>> v5->v6: >>> Follow Baoquan He's suggestion: >>> - Change some log. >>> - Add the check for acpi_rsdp >>> - Change some code logical to make code clear >>> >>> v6->v7: >>> Follow Rafael's suggestion: >>> - Add more comments and patch log. >>> Follow test robot's suggestion: >>> - Add "static" tag for function >>> >>> v7-v8: >>> Follow Kees Cook's suggestion: >>> - Use mem_overlaps() to check memory region. >>> - Use #ifdef in the definition of function. >>> >>> v8-v9: >>> Follow Boris' suggestion: >>> - Change code style. >>> - Splite PATCH 1/3 to more path. >>> - Introduce some new function >>> - Use existing function to rework some code >>> Follow Masayoshi's suggetion: >>> - Make code more readable >>> >>> v9->v10: >>> Follow Baoquan's suggestion: >>> - Change some log >>> - Merge last two patch together. >>> >>> v10->v11: >>> Follow Boris' suggestion: >>> - Link kstrtoull() instead of copying it. >>> - Drop the useless wrapped function. >>> >>> v11->v12: >>> Follow Boris' suggestion: >>> - Change patch log and code comments. >>> - Add 'CONFIG_EARLY_PARSE_RSDP' to make code easy to read >>> - Put strtoull() to misc.c >>> Follow Masa's suggestion: >>> - Remove the detection for 'movable_node' >>> - Change the code logical about cmdline_find_option() >>> >>> Any comments will be welcome. >>> >>> >>> Chao Fan (5): >>> x86/boot: Add get_acpi_rsdp() to parse RSDP in cmdline from KEXEC >>> x86/boot: Add efi_get_rsdp_addr() to find RSDP from EFI table >>> x86/boot: Add bios_get_rsdp_addr() to search RSDP in memory >>> x86/boot: Parse SRAT table from RSDP and store immovable memory >>> x86/boot/KASLR: Limit KASLR to extracting kernel in immovable memory >>> >>> arch/x86/Kconfig | 10 + >>> arch/x86/boot/compressed/Makefile | 2 + >>> arch/x86/boot/compressed/acpitb.c | 322 ++++++++++++++++++++++++++++++ >>> arch/x86/boot/compressed/kaslr.c | 79 ++++++-- >>> arch/x86/boot/compressed/misc.c | 5 + >>> arch/x86/boot/compressed/misc.h | 24 +++ >>> lib/kstrtox.c | 5 + >>> 7 files changed, 432 insertions(+), 15 deletions(-) >>> create mode 100644 arch/x86/boot/compressed/acpitb.c >>> >>> -- >>> 2.19.1 >>> >>> >>> >> >>
